PROJECT ABSTRACT The proposed South Carolina project will be a collaboration between and the University of South Carolina and the South Carolina State government (Budget and Control Board- Office for Research and Statistics). This project is possible because South Carolina has the potential to answer important questions about the health and welfare of adolescents and young adults with rare diseases using de-identified (anonymous) data from numerous agencies. For the 15-24 year age group, using only two data sources, the Hospital Discharge Data Set (HDDS) and Medicaid for the period 2000-2009, we have already identified 83 adolescents and young adults with fragile X syndrome, 635 with spinal bifida and 224 with muscular dystrophy. The project will have two parts: cross-sectional (a single point in time) and longitudinal (looking at people over an extended time period) and the study group will be 15-24 year olds with spina bifida, muscular dystrophy and fragile X syndrome. We will use linked administrative datasets (such as Medicaid, State Department of Education, and Vocational Rehabilitation) to describe the well-being and service use of the study group. We will estimate the prevalence of these conditions, their health status, educational, and employment participation. We will estimate the age specific prevalence for each condition and describe the occurrence of other acute and chronic medical conditions, including diabetes mellitus, obesity, heart disease, respiratory disease and other conditions. We will also describe the incidence and prevalence of co-morbid and secondary conditions and the co-occurrence of intellectual disability, paralysis, epilepsy, attention deficit hyperactivity disorder, and other conditions. We will also describe the frequency and type of health care received by each group, including rates of hospitalization, emergency department visits, and outpatient services, and the cost-effectiveness of different approaches to care. In the second and third year of the grant we will interview 125 affected individuals and their families to describe the living situation, education, employment, and other markers of social participation by adolescents and young adults with the three conditions, using the questionnaires from the National Longitudinal Transition Study and the RAND 36. We will describe the transition that occurs as adolescents with each condition mature into young adulthood, in terms of health care and social services (including type and specialty of health care provider by specialty, physical and occupational therapy, speech/language therapy, counseling and other services). Finally, we plan to assess the ability of other states to conduct the linked administrative data analyses and make recommendations that will be generalizable.